Bunion treating device

ABSTRACT

A pulse generating apparatus has two like output channels that apply s generated pulse signals of selected characteristics to two electrodes attached to a strap, each electrode receiving a different signal. The strap is attached to the foot so that the electrodes are positioned to stimulate with an electrical signal the abductor hallucis muscle of the foot to correct an imbalance due to overpowering by the adductor hallucis muscle in the large toe. The signal strengthens the abductor hallucis muscle so that eventually it regains strength sufficient to counter balance the imbalance effect of the stronger adductor hallucis muscle and alleviate the bunion condition in the large toe. The electrical signal generator generates signals that are pulses that are adjustable in frequency, modulation, pulse width and amplitude with modified square waves. In a second embodiment, the abductor digiti minimi brevis muscle is overpowered by the flexor digitorum (3 rd  plantar interosseus), in respect of the small toe causing Tailors Bunion. In this case, the two electrodes are attached via a strap to the foot so that the electrodes are positioned to stimulate with an electrical signal the abductor digiti minimi brevis muscle to strengthen this muscle and correct the bunion condition for the small toe.

[0001] This application is a continuation in part of application Ser.No. 09/716,567 filed Nov. 20, 2000 and incorporated by reference in itsentirety herein.

[0002] This invention relates to podiatric devices, and moreparticularly, to devices for the correction of bunion conditions in thefoot.

[0003] U.S. Pat. No. 5,665,060 discloses a bunion treatment apparatusand method for minimizing the forces applied to a bunion and includes aplanar main portion and a planar built-up portion constructed offlexible padding material. Strain relief cutouts are provided as well asa toe loop to prevent tearing of the main portion. This apparatus isprovided merely to alleviate the discomfort of the condition rather thaneliminating the condition.

[0004] U.S. Pat. No. 2,827,049 provides a bunion pad and suffers from asimilar deficiency.

[0005] U.S. Pat. No. 4,729,369 discloses a toe splint and bunioncorrection device which attempts to correct the condition with a splintdevice which straightens the toe including a splint member and a Velcrofastener for securing the splint member to the foot. The splint memberis plastic and is molded to accommodate the foot.

[0006] In U.S. Pat. No. 4,940,046 a pliable protector cushion pad deviceis disclosed for the big toe or hallux.

[0007] U.S. Pat. No. 4,632,103 shows a bandage to reduce bunion pain.

[0008] All of the above patents either try to minimize the pain of thebunion or use mechanical devices to correct the condition.

[0009]Isoelectronic Rehabilitation Program—Advanced ClinicalApplications—Podiatric Electrotherapy Applications by Joe Kleinkort,1989, 1992, is a manual that suggests electrotherapy applications forrelaxation of muscle spasm, prevention or retardation of disuse atrophy,increasing local blood circulation, muscle reeducation, immediatepostsurgical stimulation of calf muscles to prevent venous thrombosisand maintaining or increasing the range of motion. This manual disclosesplacement of electrodes to alleviate pain in various conditions in theankle, feet and knee, and stimulation of muscles in cases ofimmobilization,

[0010] An article entitled Investigations on the origin of Hallux Valgusby Electromygraphic Analysis by Takebe K. Shimazaki _(—)1 Kobe J MedicalScience 1981 Aug.: 27(4):139-58 discloses electromyographic analysis onthe physiopathology of the Hallus Valgus and toes/physiopathology.

[0011] Stephen Guffey discloses, in a publication dated 1996, musclereeducation employing electrical stimulation including frequencies,pulse duration, polarity, duty cycle, ramp, intensity, treatment time,how often, and electrode placement.

[0012] Electrode stimulation and muscle reeducation have generally beenrelated to pain reduction. None of the above articles, however, relateto the problem of bunions and how to treat and correct the condition.

[0013] The present inventor recognizes that mechanical correction of thebunion condition is not satisfactory and a need is recognized for a moresophisticated device to correct the bunion condition. The pain reductionand muscle reeducation articles using electrotherapy have dealtprimarily with leg and back problems or foot/ankle problems notassociated with bunions. Present solutions for bunions is typicallyrelated to mechanical devices as disclosed in the aforementioned patentswhich approach correcting the problem with brute force mechanicalsplints and padding.

[0014] In contrast to the mechanical devices of the prior art forcorrection of Tailors Bunion conditions in the foot, a method ofcorrecting a Tailors Bunion condition in a foot according to the presentinvention comprises the step of applying an electrical signal to theabductor digiti minimi brevis muscle to strengthen this muscle tocounter balance the strength of the flexor digitorum longus muscle andtherefore correct Tailors Bunion condition.

[0015] In one aspect, the method includes means for applying repetitivecycles of electrical pulses to the abductor digiti minimi brevis muscle.

[0016] In a further aspect, the pulses are modified square waves at apulse repetition rate of 2 Hz to 150 Hz, a pulse width of about 60:s to250:s.

[0017] The method in a further aspect includes cyclically increasing thepulse width.

[0018] In a further aspect, the method includes wrapping the foot with astrap, attaching at least one electrode to the strap with the electrodeabutting the foot and then applying the electrical signal to theelectrode.

[0019] The method in a further aspect further includes optimizing thesignal to maximize the rection by adjusting the signal parameters untilan optimum signal is generated.

[0020] A bunion correction device according to the present inventioncomprises means for attaching at least one electrode to the foot forapplying an electrical signal to the abductor digiti minimi brevismuscle in the foot for strengthening this muscle to counter balance thestrength of the foot flexor digitorum muscle and signal generator meansfor generating the electrical signal and applying the generated signalto the means for attaching.

[0021] In one aspect, the means for attaching comprises strap means forencircling the foot and means for securing the at least one electrode tothe strap means for abutting the foot when the strap means is attachedto the foot.

[0022] In a further aspect, the generating means includes means forapplying a generated signal to two electrodes.

[0023] In a further aspect, the signal generator includes means forgenerating a plurality of pulses and includes means for setting thepulses in the range of 0-80 mA peak with either a positive or negativepulse into a 500 ohm load.

[0024] In a further aspect, the means for generating includes means forgenerating the pulse at a frequency in the range of about 2 Hz to 150Hz.

[0025] In a further aspect, the means for generating includes means forgenerating the pulse with a width in the range of about 60:s to 250:s.

[0026] In a still further aspect, the means for generating includesmeans for generating bursts of said pulses of about 7 pulses at amaximum pulse rate.

[0027] In a further aspect, the means for generating includes means forgenerating bursts of pulses twice a second.

[0028] In a further aspect, the strap means comprises a strap forencircling the foot.

[0029] In a still further aspect, two spaced electrodes are arranged onthe strap means for overlying the abductor digiti minimi brevis muscleof the foot in two spaced locations.

[0030] In a further aspect, the means for generating includes means forindependently generating the two signals and applying a different signalto each electrode.

IN THE DRAWING

[0031]FIG. 1 is a perspective view of a foot exhibiting a bunioncondition;

[0032]FIG. 2 is a top plan view of the anatomy of a foot showing theabductor hallucis muscle in the foot;

[0033]FIG. 3 is a top plan view of the anatomy of a foot showing theabductor hallucis and adductor muscles (cut away) in the foot whichcontrol the large toe;

[0034]FIGS. 4 and 5 are respective similar side views of a foot whichshow generally the placement of electrodes for the correction of thebunion condition and a device according to an embodiment of the presentinvention employing electrodes for the correction of the bunioncondition with electrical signals;

[0035]FIG. 6 is a plan view of the foot and device of FIG. 5;

[0036]FIG. 7 is a plan view of the device of FIGS. 5 and 6 prior toattachment to a foot with representative electrodes attached forelectrically correcting the bunion condition;

[0037]FIG. 8 is a front elevation view of an electrical signal generatorfor use with the device of FIGS. 5, 6 and 7;

[0038]FIG. 9 is a top plan view of the generator of FIG. 8;

[0039]FIGS. 10a and 10 b are waveform graphs of representative signalsproduced by the generator of FIG. 8;

[0040]FIG. 11 is an isometric view of a portion of the top of thegenerator of FIG. 9 showing the attachment of a the signal output cableof the generator to a representative output connector, there being twooutput connectors in the generator; and

[0041]FIG. 12 is a top plan view of a representative electrode forapplying a bunion correction signal to the foot;

[0042]FIG. 12a is an isometric view of the electrode of FIG. 12 withoutthe electrical terminal in place;

[0043]FIG. 13 is a top plan view of the anatomy of a foot showing theabductor digiti V and flexor digitorum muscles in the foot;

[0044]FIG. 14 is a view of the distorted bones of the small toe due toTailors Bunion condition;

[0045]FIG. 15 is a is a plan view of the foot and device of FIG. 17 inplace;

[0046]FIG. 16 is a side view of a foot similar to FIG. 4 showinggenerally the placement of electrodes for the correction of the TailorsBunion condition in the small toe according to an embodiment of thepresent invention employing electrodes for the correction of the TailorsBunion condition with electrical signals; and

[0047]FIG. 17 is a plan view of the device of FIG. 15 prior toattachment to a foot with representative electrodes attached forelectrically correcting the Tailors Bunion condition

[0048] In FIG. 1, foot 10 big toe 12 has a bunion 14. In FIG. 2, onemuscle of the foot for controlling the big toe is the abductor hallucismuscle 16. In FIG. 3, a second muscle of the big toe is the adductorhallucis muscle 18 (shown cut away but in practice has an extentcorresponding generally to the extent of the abductor hallucis muscle inFIG. 2. The present invention is a result of the recognition that thebunion 14 (shown in phantom in FIG. 3) is caused by the adductorhallucis muscle becoming stronger than the abductor hallucis muscle.Normally, in a healthy foot both muscles are of equal strength andcounter balance the forces of each other in the normal quiescent stateof the big toe.

[0049] However, over time due to mis-fitting shoes or due to genetic ordisease problems, the strengths of the two muscles become different. Theadductor muscle eventually overpowers the abductor muscle and pulls thebig toe over to one side toward the other toes as shown in phantom inFIG. 3 by toe 12′. The abductor muscle extends for the length of thefoot as shown in FIG. 1 and is adjacent to both the side and top sidesurfaces of the foot.

[0050] It is known generally that muscles can be stimulated byelectrical signals and this knowledge has been used to relieve pain dueto muscle conditions, typically in the back, foot, ankle or leg. See thearticles in the introductory portion. However, the present invention isa recognition that the bunion is due to a imbalance in the abductor andadductor hallucis muscles and that the abductor muscle can bestrengthened by the application of electrical pulses thereto. The priorart has typically approached the correction of bunions with brute forceby the use of mechanical devices and splints. The use of electricalsignals to strengthen the abductor hallucis muscle of the presentinvention corrects the problem by reducing the one sided impactimbalance of the stronger adductor hallucis muscle in persons exhibitingbunions.

[0051] In FIG. 4, foot 10 is shown with a region 20 in which theabductor hallucis muscle is located. One or more electrodes are placedin this region and an electrical signal is applied to the electrodes tostimulate and repetitively relax and tighten the abductor hallucismuscle. The exact location can be determined empirically for eachpatient in order to ascertain the most optimum portion of the abductorhallucis muscle that is responsive to the electrical signal(s) forstrengthening the muscle. This might take some trial and error until theoptimum repositioning of the big toe 12 is observed. It is recommendedthat the major site of the abductor hallucis muscle be identified andthe electrodes applied to this site. This site is believed to occur inthe region 24, FIG. 2, in regard to the abductor hallucis muscle, whichmight vary of course from individual to individual.

[0052] In FIG. 7, device 26 comprises a strap 28 formed of felt, foam orsimilar soft cushioning materials the composition of which is notimportant to the present invention other than it be electricalinsulating material. Strap 28 preferably comprises two substraps 30 and32. Substrap 30 comprises a generally rectangular member with twoopposing legs 34 and 36 of about the same width and attached one pieceand integral with connecting member 38. Legs 34 and 36 are of like widthfrom left to right in the figure. The end 40 of leg 36 has a strip 42 ofVelcro hook members, a trademark for a hook and loop fastener well knownand commercially available. The leg 34 and leg 36 overlap when wrappedabout the foot as shown in FIGS. 5 and 6. The leg 36 strip 42 hooksengage the leg 34 which comprises loop type of fabric, or in thealternative, may include a strip (not shown) of Velcro loop materialmating with the hook material strip 42. The hook and loop materialreleasably attach the overlapping two legs 34 and 36 of the substrap 30as shown.

[0053] Substrap 32 comprises two legs 44 and 46 and Velcro hook strip48. Legs 44 and 46 attach similarly as legs 34 and 36 about the big toe12. Substrap 32 is connected to substrap 30, and integral one piecetherewith by the connecting member 38. In FIG. 7, two electrodes 50 and52 in this embodiment are attached to substrap 30 The electrodes 50 and52 are identical and a description of electrode 50 is representative. InFIGS. 12 and 12a, electrode 50 comprises a electrically conductive pad54 which may be conductive elastomeric or plastic material. The pad 54has a hollow somewhat tubular terminal connector 56 molded integraltherewith. The pad 54 is square but may be other shapes. This electrode50 is commercially available from the Lumiscope Company of Edison, N.J.as a kit with other components of the electrical signal generator to bedescribed below as model SW1000 Transcutaneous Electrical NerveStimulator.

[0054] An electrical terminal 58 which is an elongated metal wire astypical in electrical connections and terminals, fits inside of theconnector 56 to apply an electrical pulse signal to the pad 54. The pad54 on a side opposite the connector 54 may receive an electricallyconductive gel as known in this art for providing good electricalcoupling to a local applied portion of the skin of the foot 10. Anelectrically conductive conductor 60 is connected to terminal 58 at oneconductor end and to plug connector 62, FIG. 11, at the other conductorend.

[0055] In FIG. 8, electrical signal generator apparatus 64 has a housing66 which receives a battery 68 (a conventional 9 volt transistorbattery) with its electrical connection to the apparatus 64 and thehousing cover not shown. The apparatus has a circuit which iscommercially available (not shown and within the housing) and isavailable from the Lumiscope Company. Two control knobs 70 and 72control the respective pulse width and frequency of the alternatingcurrent signal produced by the apparatus 64. A mode selector switch 74selects burst (B), normal (N) and modulation (M) modes of the generatedpulses. A power indicator light 76 is included. In FIG. 9, channeloutput receptacles 78 and 80 provide two parallel identical outputsignals generated by the apparatus 64. Knob 82 controls channel on/offstate for receptacle 80 and the output signal amplitude for thisreceptacle. Knob 84 controls channel on/off state for receptacle 78 andthe output signal amplitude for this receptacle.

[0056] The circuit of apparatus 64 provides dual identical channelswhich are electrically isolated. The circuit is a pulse generator forgenerating approximate adjustable square waves as shown in FIGS. 10a and10 b which are self explanatory. The amplitude of each channel isindependently controlled, but otherwise the parameters of the signals ofthe two channels is the same as controlled by knobs 70 and 72 and modeselect switch 74. The pulse amplitude is adjustable by knobs 82 and 84in a range of 0-80 mA peak either with a positive pulse or negativepulse into a 500 ohm load for each channel. The pulse frequency isadjustable in the range of 2 Hz to 150 Hz. The pulse width is adjustablein the range of about 60:μs to 250:μs.

[0057] The apparatus has a modulation mode. The modulation mode is onewhere the pulse width is automatically varied in a cyclic pattern overan interval of nominally 4.0 seconds. The pulse width decreases linearlyover a period of 1.0 seconds from the control setting value to a valuewhich is decreased 40% maximum. The narrow pulse width will continue for1.5 seconds maximum, then increase linearly over a 1.5 second period toits original value. The cycle is then repeated.

[0058] The apparatus also has a burst mode in which bursts of sevenpulses are provided at a maximum pulse rate. The bursts occur twice asecond.

[0059] The wave form as shown in FIGS. 10a and 10 b are modified squarewaves with zero net direct current (DC) component. All of the adjustableparameters are set at the midpoint of the specified range. The apparatushas a voltage of 0-110 volts maximum either positive or negative pulse(open circuit). There is a maximum charge per pulse of 16 microcoulombs. The values may vary in a range of +/−20%. This apparatus isnormally commercially available for treatment only of pain, chronic oradjunct to management of post surgical and post traumatic acute painproblems. However, as disclosed herein it may also be used to correctbunion conditions. The apparatus is available with the restriction thattranscutaneous electrical nerve stimulation is of no known curativevalue other than pain relief.

[0060] The connector 62 is mated in receptacle 78, FIG. 1 1to connectthe electrode 50 to the output signal. The electrodes 50 and 52, FIG. 7,are bonded by a Velcro fastener to the strap 28, FIG. 7, leg 36. Thelocation of the electrodes is determined for a given patient anddetermined on a case by case basis. The signal parameters are varieduntil optimum correction of the bunion is noted. This requires settingof the pulse parameters by the user during the initial set up. The userwill note various nerve reactions to the electrical signals and byobservation can determine optimum electrical impulses. The variousparameters of the pulses are set to optimize the visual and physicalresults. While the particular electrical signal parameters are givenherein, they are given by way of example, and not limitation. Otherelectrical signals of pulses of different shapes, currents, amplitudesand wave forms may also be used according to a given condition beingcorrected. Also, the shape and material of the strap is by way ofexample and not limitation.

[0061] Other devices for applying the electrical signals may beutilized, the device described herein being given by example only. Theimportant aspect is that the abductor muscle is strengthenedsufficiently so that the forces on the big toe muscles balance. The bigtoe thus returns to its normal position in response to the treatmentdescribed herein.

[0062] In FIG. 14, a second bunion condition is shown in the foot. Thiscondition is known as Tailors Bunion. The small toe 86 bone 88 (thefifth toe) is pulled inward toward toe 92 (the fourth toe) relative tobone 90. The bone 88 is bent at joint 94. In FIG. 13, this bunioncondition in caused in foot 96 by the stronger muscle flexor digitorumlongus overpowering the weaker muscle abductor digiti v. or otherwiseknown as the abductor digiti minimi brevis.

[0063] In FIG. 15, the foot 96 small toe 98 is shown electricallyadjusted by impulses produced by device 99. In FIG. 17, device 99comprises a strap 100 to which two electrodes 50′ and 52′ (which may beidentical to electrodes 50 and 52) are attached in a manner similar tothe attachment of electrodes 50 and 52, FIG. 7. Electrodes 50′ and 52′are also operated similarly as electrodes 50 and 52 by pulse generator64, FIG. 8, described above, except in this case the pulse parametersand electrode positions are adjusted accordingly to correct for theTailors Bunion condition. This adjustment and the level of currents andpulse parameters are also determined empirically for eachimplementation.

[0064] In FIG. 16, foot 96 is shown with a region 104 in which theabductor digiti minimi brevis muscle is located. One or more electrodes102 corresponding to electrodes 50′ and 52′ are placed in this regionand an electrical signal is applied to the electrodes to stimulate andrepetitively relax and tighten the abductor digiti minimi brevis muscle.The exact location can be determined empirically for each patient inorder to ascertain the most optimum portion of the abductor digitiminimi brevis muscle that is responsive to the electrical signal(s) forstrengthening the muscle. This might take some trial and error until theoptimum repositioning of the small toe 98 is observed. It is recommendedthat the major site of the abductor digiti minimi brevis muscle beidentified and the electrodes applied to this site. This site isbelieved to occur in the region 104, FIG. 16, in regard to the abductordigiti minimi brevis muscle, which might vary of course from individualto individual.

[0065] In FIG. 15, the foot 96 small toe 98 is shown electricallyadjusted by impulses produced by device 99. In FIG. 17, device 99comprises a strap 100 to which two electrodes 50′ and 52′ (which may beidentical to electrodes 50 and 52) are attached in a manner similar tothe attachment of electrodes 50 and 52, FIG. 7. Electrodes 50′ and 52′are also operated similarly as electrodes 50 and 52 except in this casethe pulse parameters and electrode positions are adjusted accordingly tocorrect for the Tailors Bunion condition. This adjustment and the levelof currents and pulse parameters are also determined empirically foreach implementation.

[0066] In FIG. 17, device 98 strap 100 is also formed of felt, foam orsimilar soft cushioning materials the composition of which is notimportant to the present invention other than it be electricalinsulating material similarly as strap 28 described above. Strap 100preferably comprises two substraps 104 and 106. Substrap 104 comprises agenerally rectangular member with two opposing legs 108 and 110 of aboutthe same width and attached one piece and integral with connectingmember 112. Legs 108 and 110 are of like width from left to right in thefigure. The end 114 of leg 108 has a strip 116 of Velcro hook members.The legs 108 and 110 overlap when wrapped about the foot as shown inFIG. 15. The strip 116 hooks engage the leg 110 which comprises looptype of fabric, or in the alterative, may include a strip (not shown) ofVelcro loop material mating with the hook material strip 116.67]Substrap 32 comprises two legs 118 and 1120 and Velcro hook strip122. Legs 118 and 120 attach about the small toe 98. Substraps 118 and120 are integral one piece and attached to connecting member 112. Twoelectrodes 50′ and 52′ in this embodiment are attached to substrap 108.The electrodes 50′ and 52′ may be identical and are as described abovein connection with electrodes 50 and 52.

[0067] While a strap is shown about the big and small toes these areoptional and are provided in case a need arises for electrodes to beattached thereto.

[0068] It will occur to one of ordinary skill that modifications may bemade to the disclosed embodiments without departing from the scope ofthe invention as defined in the appended claims. The disclosedembodiments are given by way of illustration and not limitation. Forexample, while the foot muscles for the big toe involving a bunioncondition are corrected herein, other muscles involving other limbdistortions due to muscle imbalance may also be corrected by applyingelectrical signals to strengthen certain of such other muscles.

What is claimed is:
 1. A bunion correction device comprising: means forattaching at least one electrode to the foot for applying an electricalsignal to the abductor digiti minimi brevis muscle in the foot forstrengthening the abductor digiti minimi brevis muscle to counterbalance the strength of the foot flexor digitorum muscle to correct abunion in the small toe; and signal generator means for generating theelectrical signal and applying the generated signal to the at least oneelectrode.
 2. The device of claim 1 wherein the means for attachingcomprises strap means for encircling the foot and means for securing theat least one electrode to the strap means for abutting the foot when thestrap means is attached to the foot.
 3. The device of claim 1 whereinthe generating means includes means for applying a generated signal totwo electrodes.
 4. The device of claim 1 wherein the signal generatorincludes means for generating a plurality of pulses and includes meansfor setting the pulses in the range of 0-80 mA peak with either apositive or negative pulse into a 500 ohm load. 176746-3
 5. The deviceof claim 4 wherein the means for generating includes means forgenerating the pulse at a frequency in the range of about 2 Hz to 150Hz.
 6. The device of claim 4 wherein the means for generating includesmeans for generating the pulse with a width in the range of about 60:sto 250:s.
 7. The device of claim 4 wherein the means for generatingincludes means for generating bursts of said pulses of about 7 pulses ata maximum pulse rate.
 8. The device of claim 4 wherein the means forgenerating includes means for generating bursts of pulses twice asecond.
 9. The device of claim 2 wherein the strap means comprises astrap for encircling the foot.
 10. The device of claim 2 including twospaced electrodes arranged on the strap means for overlying the abductordigiti minimi brevis muscle of the foot in two spaced locations.
 11. Thedevice of claim 3 wherein the means for generating includes means forindependently generating the two signals and applying a different signalto each electrode.
 12. A method of correcting a bunion condition in afoot comprising the step of applying an electrical signal to theabductor digiti minimi brevis muscle to strengthen the abductor digitiminimi brevis muscle and counter balance the strength of the flexordigitorum muscle to correct for an imbalance between the two muscles.13. The method of claim 12 including the step of applying repetitivecycles of electrical pulses to the abductor muscle.
 14. The method ofclaim 13 including the step of generating pulses that are modifiedsquare waves at a pulse repetition rate of 2 Hz to 150 Hz and at a pulsewidth of about 60:s to 250:s.
 15. The method of claim 14 including thestep of cyclically increasing the pulse width.
 16. The method of claim15 including the step of varying the pulse width in repetitive foursecond cycles.
 17. The method of claim 12 including the step of wrappingthe foot with a corresponding strap, attaching at least one electrode tothe strap with the electrode abutting the foot and then applying theelectrical signal to the electrode.
 18. The method of claim 12 includingoptimizing the signal to maximize said correction by adjusting thesignal parameters until an optimum signal is generated.
 19. The methodof claim 12 including periodically applying the signal to the foot. 20.The method of claim 19 including applying the signal in the range of15-30 minutes daily.
 21. The method of claim 12 including cyclicallytightening and relaxing the abductor digiti minimi brevis muscle withthe electrical signal in repetitive periods.